This article will aim to answer the essential questions you have before purchasing a gas sensor.
If you have any other questions, or require more personalised information for your application, then please contact us and a member of our team will be happy to help!
Cross-sensitivity in gas detection is when a sensor reacts to a gas other than its intended target, leading to inaccurate or false readings. This is caused by the overlapping of infrared absorption bands between the target gas and the interfering gas.
For example, the methane Gascard responds to other hydrocarbons or compounds with carbon-hydrogen bonds such as ethane, propane, ethylene, alcohols, etc. This means it is possible for a 0-100% methane sensor to read higher than 100% due to the presence of small quantities of these compounds.
When purchasing a product from us, if you provide information about your application and background gases we will be able to offer advice and support on which product will work best for your application.
2. Does the presence of hydrogen affect the gas sensor?
Large quantities of hydrogen can negatively impact your sensor by reducing the lifetime of the infrared lamp. The hydrogen diffuses through the glass bulb and reacts with the tungsten filament causing it to become brittle and eventually to fail.
If you are concerned about high levels of hydrogen affecting the lifespan of your sensor, you can get in touch and we can provide support to mitigate these affects.
3. Can your Sensor withstand high pressure and temperature environments?
Yes – we can withstand harsh environments and have several additional features to support this.
For example, we have an on-board temperature and pressure correction system, which allows the gas sensor to work in more demanding environments.
4. Can high humidity affect my gas readings?
Humidity can affect your gas readings – its important to understand what type of humidity is present and in what quantities. Based on this our team can recommend any relevant accessories to mitigate the effects of high humidity.
We can support humidity conditions up to 95% as long as it’s non-condensing humidity, we also offer an external water trap which would prevent water from entering the sensors optical components in high humidity.
If you have a high humidity environment and are unsure which product and accessories would work best for you, then please get in touch and we would be happy to provide support.
6. Can corrosive gases affect the lifespan of the units?
Corrosive gases like HCL and SO2 can potentially shorten the lifespan of the Gascard. However, ensuring a suitable operating environment and consistent unit maintenance will help protect the sensor from these harmful gases.
Higher concentrations of these gases and the presence of moisture can have a greater affect, but we also have customers who utilize our products in the presence of these gases with no issues on their product.
7. What is the minimum detection limit of the Gascard / Guardian?
We don’t normally specify a single limit of detection (LOD), as this value is highly dependent on the sensors setup, operating environment, and usage parameters.
To offer a working estimate on this limit, we tested a 500ppm CO2 Gascard using zero gas and observed a standard deviation (noise level) of 0.35ppm CO2 .If we define the LOD as 3.3 times this value, the sensor should show a visible response to a change of 1.16 ppm CO2.
Overall, this limit can change on a case by case basis, and so if you require additional information which is tailored to your application – please feel free to reach out.
Other questions?
If you have any other questions, or require specific advice for your application – please get in touch with our team, and we would be happy to provide support and advice.
